2001 TOYOTA AVALON air condition

- DIAGNOSTICSENGINE
DI-49
205 Author
: Date
:
2001 AVALON (RM808U)
DTC P0136 Oxygen Sensor Circuit Malfunction (Bank 1
Sensor 2)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page DI-43.
DTC No.DTC Detecting ConditionTrouble Area
P0136
Voltage output of heated oxygen sensor remains at 0.4 V or
more or 0.55 V or less when vehicle is driven at 50 km/h (31
mph) or more after engine is warmed up (2 trip detection logic)
Open or short in heated oxygen sensor circuit

Heated oxygen sensor
HINT:

Bank 1 refers to the bank that includes cylinder No.1.

Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to DTC P0125 on page DI-43.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining
whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean
or rich, etc. at the time of the malfunction.
1 Are there any other codes (besides DTC P0136) being output?
YES Go to relevant DTC chart (See page DI-14).
NO
2 Check for open and short in harness and connector between ECM and heated
oxygen sensor (See page IN-30).
NG Repair or replace harness or connector.
OK
DI07Q-09

A06104
ON
HTS
(+)
(-)
- DIAGNOSTICSENGINE
DI-51
207 Author
: Date
:
2001 AVALON (RM808U)
DTC P0141 Oxygen Sensor Heater Circuit Malfunction
(Bank 1 Sensor 2)
CIRCUIT DESCRIPTION
Refer to DTC P0125 on page DI-43.
DTC No.DTC Detecting ConditionTrouble Area
P0141
When heater operates, heater current exceeds 2.35 A (2 trip
detection logic)
Open or short in heater circuit of heated oxygen sensor
Htd htP0141Heater current of 0.2 A or less when heater operates (2 trip
detection logic)
Heated oxygen sensor heater

ECM
HINT:

Bank 1 refers to the bank that includes cylinder No.1.

Sensor 2 refers to the sensor farther away from the engine body.
WIRING DIAGRAM
Refer to DTC P0125 on page DI-43.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining
whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean
or rich, etc. at the time of the malfunction.
1 Check voltage between terminal HTS of ECM connector and body ground.
PREPARATION:
(a) Remove the glove compartment (See page SF-82).
(b) Turn the ignition switch ON.
CHECK:
Measure the voltage between terminal HTS of the ECM con-
nector and body ground.
OK:
Voltage: 9 - 14 V
OK Check and replace ECM (See page IN-30).
NG
2 Check resistance of heated oxygen sensor heater (See page SF-81).
NG Replace heated oxygen sensor.
DI6T3-01

DI-58
- DIAGNOSTICSENGINE
214 Author
: Date
:
2001 AVALON (RM808U)
DTC P0300 Random/Multiple Cylinder Misfire Detected
DTC P0301 Cylinder 1 Misfire Detected
DTC P0302 Cylinder 2 Misfire Detected
DTC P0303 Cylinder 3 Misfire Detected
DTC P0304 Cylinder 4 Misfire Detected
DTC P0305 Cylinder 5 Misfire Detected
DTC P0306 Cylinder 6 Misfire Detected
CIRCUIT DESCRIPTION
Misfire: The ECM uses the crankshaft position sensor and camshaft position sensor to monitor changes in
the crankshaft rotation for each cylinder.
The ECM counts the number of times the engine speed change rate indicates that misfire has occurred.
When the misfire rate equals or exceeds the count indicating that the engine condition has deteriorated, the
MIL lights up.
If the misfire rate is high enough and the driving conditions will cause catalyst overheating, the MIL blinks
when misfiring occurs.
DTC No.DTC Detecting ConditionTrouble Area
P0300Misfiring of random cylinders is detected during any particular
200 or 1,000 revolutions
Open or short in engine wire

Connector connection

Vacuum hose connection
P0301
P0302
P0303For any particular 200 revolutions for engine, misfiring is de-
tected which can cause catalyst overheating (This causes MIL
to blink)

Ignition system

Injector

Fuel pressure

Mass air flow meter

Engine coolant tempsensorP0303
P0304
P0305
P0306For any particular 1,000 revolutions of engine, misfiring is de-
tected which causes a deterioration in emission (2 trip detec-
tion logic)

Engine coolant temp. sensor

Compression pressure

Valve clearance

Valve timing

ECM
DI07S-10

DI-60
- DIAGNOSTICSENGINE
216 Author
: Date
:
2001 AVALON (RM808U)
(e) Check whether there is misfire or not by monitoring DTC and the freeze frame data. After that, record
them.
(f) Turn the ignition switch OFF and wait at least 5 seconds.
INSPECTION PROCEDURE
HINT:

If is case that DTC besides misfire is memorized simultaneously, first perform the troubleshooting for
them.

Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame
data records the engine conditions when the malfunction is detected. When troubleshooting, it is useful
for determining whether the vehicle was running or stopped, the engine was warmed up or not, the
air-fuel ratio was lean or rich, etc. at the time of the malfunction.

When the vehicle is brought to the workshop and the misfire is not occurred, misfire can be confirmed
by reproducing the condition or freeze frame data. Also, after finishing the repair, confirm that there
is no misfire. (See the confirmation driving pattern)

When either of SHORT FT #1, LONG FT #1, SHORT FT #2 or LONG FT #2 in the freeze frame data
is besides the range of ±20 %, there is a possibility that the air-fuel ratio is inclining either to ºrichº (-20
% or less) or ºleanº (+20 % or more).

When COOLANT TEMP in the freeze frame data is less than 80°C (176°F), there is a possibility or
misfire only during warming up.

In the case that misfire cannot be reproduced, the reason may be because of the driving with lack or
fuel, the use of improper fuel, a stain of ignition plug, and etc.
1 Check wire harness, connector and vacuum hose in engine room.
CHECK:
(a) Check the connection conditions of wire harness and connector.
(b) Check the disconnection, piping and break of vacuum hose.
NG Repair or replace, then confirm that there is no
misfire (See the confirmation driving pattern).
OK

A00304
Knock SensorECM
EB1
Male
ConnectorFemale
Connector 1
111
22KNKR
KNKL
EB1
E4
E427
28
FI7050
S06024
S06025
FI6510FI6607A00113
KNK Signal Waveform
0.5 V
/Division
5 msec./Division
100 msec./Division 0V
200 mV
/Division
0V
- DIAGNOSTICSENGINE
DI-65
221 Author
: Date
:
2001 AVALON (RM808U)

Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for
determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel
ratio was lean or rich, etc. at the time of the malfunction.
1 Connect OBD II scan tool or TOYOTA hand-held tester, and check knock sensor
circuit.
PREPARATION:
(a) Connect the OBD II scan tool or TOYOTA hand-held tes-
ter to the DLC3.
(b) Disconnect the wire from wire connector EB1.
(c) Connect the terminals of the disconnected EB1 male con-
nector and EB1 female as follows.
Male connector eFemale connector
Terminal 1 e Terminal 2
Terminal 2 e Terminal 1
(d) Turn the ignition switch ON and push the OBD II scan tool
or TOYOTA hand-held tester main switch ON.
(e) After the engine is warmed up, perform quick racing to
4,000 rpm 3 times.
CHECK:
Check the DTC.
RESULT:
Type IDTC same as when vehicle brought in
P0325 " P0325 or P0330 " P0330
Type IIDTC different to when vehicle brought in
P0325 " P0330 or P0330 " P0325
Reference: INSPECTION USING OSCILLOSCOPE

With the engine racing (4,000 rpm), check the waveform
between terminals KNKR, KNKL of the ECM connector
and body ground.
HINT:
The correct waveform is as shown.

Spread the time on the horizontal axis, and confirm that
period of the wave is 141 msec. (Normal mode vibration
frequency of knock sensor: 7.1 kHz)
HINT:
If normal mode vibration frequency is not 7.1 kHz, the sensor
is malfunctioning.
Type II Go to step 3.

A11084
Right Bank VVT Sensor (Camshaft Position Sensor)
Crankshaft Position Sensor1
2
1
2
B-W B-W
L
L16
2410ECM
VV1+
NE+
NE-
E2
21LB-W
LE4
E5
VV2+ 22 Left Bank VVT Sensor (Camshaft Position Sensor)E5
E4 CC
C
CJ8 J/C
- DIAGNOSTICSENGINE
DI-67
223 Author
: Date
:
2001 AVALON (RM808U)
DTC P0335 Crankshaft Position Sensor ºAº Circuit Mal-
function
CIRCUIT DESCRIPTION
Crankshaft position sensor (NE signal) consists of a magnet, iron core and pickup coil.
The NE signal plate has 34 teeth and is installed the crankshaft timing pulley. The NE signal sensor gener-
ates 34 signals at every engine revolution. The ECM detects the standard crankshaft angle based on the
G (VV) signal, and the actual crankshaft angle and the engine speed by the NE signal.
DTC No.DTC Detecting ConditionTrouble Area
P0335
No crankshaft position sensor signal to ECM during cranking
(2 trip detection logic)
Open or short in crankshaft position sensor circuit

Crankshaft position sensor
P0335No crankshaft position sensor signal to ECM with engine
speed 600 rpm or more (2 trip detection logic)

Crankshaft osition sensor

Crankshaft timing pulley

ECM
WIRING DIAGRAM
INSPECTION PROCEDURE
HINT:

Perform troubleshooting of DTC P0335 first. If no trouble is found, troubleshoot the following mechani-
cal systems.

Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame
records the engine conditions when the malfunction is detected. When troubleshooting, it is useful for
determining whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel
ratio was lean or rich, etc. at the time of the malfunction.
DI07U-09

- DIAGNOSTICSENGINE
DI-69
225 Author
: Date
:
2001 AVALON (RM808U)
DTC P0340 Camshaft Position Sensor Circuit Malfunc-
tion
CIRCUIT DESCRIPTION
Camshaft position sensor (G (VV) signal) consists of a magnet, iron core and pickup coil.
The G (VV) signal plate has 3 teeth, on its outer circumference and is installed the camshaft timing gear.
When the camshafts rotate, the protrusion on the signal plate and the air gap on the pickup coil change,
causing fluctuations in the magnetic field and generating an electromotive force in the pickup coil.
The NE signal plate has 34 teeth and is installed the crankshaft timing pulley. The NE signal sensor gener-
ates 34 signals at every engine revolution. The ECM detects the standard crankshaft angle based on the
G (VV) signal and the actual crankshaft angle and the engine speed by the NE signal.
DTC No.DTC Detecting ConditionTrouble Area
P0340
No camshaft position sensor signal to ECM during cranking (2
trip detection logic)
Open or short in camshaft position sensor circuit

Camshaft position sensor
P0340No camshaft position sensor signal to ECM with engine speed
600 rpm or more

Camshaft osition sensor

Camshaft timing gear

ECM
WIRING DIAGRAM
Refer to DTC P0335 on page DI-67.
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining
whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean
or rich, etc. at the time of the malfunction.
1 Check resistance of camshaft position sensor (See page IG-1).
Reference: INSPECTION USING OSCILLOSCOPE
Refer to DTC P0335 on page DI-67.
NG Replace camshaft position sensor.
OK
2 Check for open and short in harness and connector between ECM and camshaft
position sensor (See page IN-30).
NG Repair or replace harness or connector.
DI07V-09

A00479
Engine Speed
3,000 rpm
Idling
IG SW OFF
Warmed up
3 min. or so
CheckTime (a)(c) (d)
(b) 2,000 rpm
2 sec. 2 sec.
DI-72
- DIAGNOSTICSENGINE
228 Author
: Date
:
2001 AVALON (RM808U)
CONFIRMATION ENGINE RACING PATTERN
(a) Connect the OBD II scan tool or TOYOTA hand-held tester to the DLC3.
(b) Start engine and warm it up with all the accessories switched OFF until the water temperature is stable.
(c) Race the engine at 2,500 - 3,000 rpm for about 3 min.
(d) When racing the engine at 3,000 rpm for 2 sec. and 2,000 rpm for 2 sec. alternately, check the wave-
form of the heated oxygen sensor (bank 1 sensor 2).
INSPECTION PROCEDURE
HINT:
Read freeze frame data using TOYOTA hand-held tester or OBD II scan tool. Because freeze frame records
the engine conditions when the malfunction is detected. When troubleshooting, it is useful for determining
whether the vehicle was running or stopped, the engine was warmed up or not, the air-fuel ratio was lean
or rich, etc. at the time of the malfunction.
1 Are there any other codes (besides DTC P0420) being output?
YES Go to relevant DTC chart (See page DI-14).
NO
2 Check gas leakage on exhaust system.
NG Repair or replace.
OK